流动注射在线过滤稀释原子吸收法测定诺氟沙星

提出了流动注射在线过滤稀释原子吸收法测定诺氟沙星的新方法。药物浓度在0．1－0．8mg/mL范围符合比耳定律，回收率为97．9％－102．4％，相对标准偏差为1．7％。方法可用于诺氟沙星胶囊测定。     

STUDENT TEACHERS’ UNDERSTANDING OF RATIONAL NUMBER: PART-WHOLE AND NUMERICAL CONSTRUCTS

Previous research has shown that secondary school students’ understanding of fractions is dominated by the part-whole concept to the possible detriment of their understanding of a fraction as a number in its own right. The present paper reports on an investigation into the understanding of intending primary teachers in this area. Four representatives of a cohort of sixty students on a PGCE course specialising in the lower primary age range were asked detailed questions probing their knowledge of fractions. The conclusion was that the part-whole concept dominates. All of the students were familiar with the numerical concept from their work on the PGCE course, but they reverted to the more familiar part-whole ideas in attempting to solve problems.     

Teachers’ conceptions of tangent line

In order to study the conceptions, and their evolutions, of the tangent line to a curve an updating workshop which took place in México was designed for upper secondary school teachers. This workshop was planned using the methodology of cooperative learning, scientific debate and auto reflection (ACODESA) and the conception-knowing-concept model (cK¢) developed mainly by Balacheff. In order to initiate the conceptions reorganization, an initial activity was made in the graphic frame; it seems optimal to start the debates without leading participants to failure. The mathematical core of the workshop was formed by an algebraic method to find tangents to algebraic curves which is close to Descartes’ method. The ACODESA methodology allowed some intense debates mainly concerning the local character of a tangent, generating the teachers’ cognitive unbalance which is a starting point for the refinement or transformation of their conceptions. On the other hand, the cK¢ model allows to understand the conceptions of participants and to analyze the evolution of their knowings.     

90Mo电磁跃迁几率的测量

利用束流能量为116MeV的⁵⁹Co(³⁵Cl,2p2n)⁹⁰Mo反应布居⁹⁰Mo的高自旋态.用10台反康普顿HPGe探测器组成的探测阵列进行γγ符合测量.通过多普勒展宽峰的形状分析测定⁹⁰Mo高自旋态的寿命.在正宇称衰变系观察到增强的M1跃迁,推断I=13以上是扁椭形变.负宇称高自旋态具有大的B(E2)值,并随自旋增大而起伏变化.正、负宇称态之间的跃迁显示增大的E1跃迁,似有八极关联的可能.但是,⁹⁰Mo并不处在理论预言的存在八极形变的核区内.     

Efficient generalized conjugate gradient algorithms,part 1: Theory

The effect of inexact line search on conjugacy is studied in unconstrained optimization. A generalized conjugate gradient method based on this effect is proposed and shown to have global convergence for a twice continuously differentiable function with a bounded level set.     

On the Helly Number for Line Transversals to Parallel Triangles

We prove two results about the problem of finding the Helly number for line transversals to a family of parallel triangles in the plane: (1) If each three triangles of a family of parallel right triangles are intersected by an ascending (or a descending) line, then there is an ascending (or a descending) line that intersects all     

High power 1341.4 nmNd:YAlO3 CW laser and its performances

A lamp pumped high power 1341.4 nmNd:YAlO₃CW laser and its performances have been described. As high as 188 W of CW output power has been obtained at 1341.4 nm alone line with a overall efficiency of 1.37% and a slope efficiency of 2.14%. The divergence (FWHM) and instability (RMS) of this laser at output power of 155 W are 15 mrad and 1.19%, respectively.     

一般Hopf曲面上的一类全纯线丛的上同调维数的计算公式

研究了具有任意基本群的非主Hopf流形上的全纯线丛．我们利用推广了Douady序列，利用群作用的方法，具体给出了一类具有非交换基本群的Hopf曲面上全纯线丛上同调维数的计算公式。